Coating machine



Dec 15, 1942. R, HEN Y 2,305,005.

comma MACHINE Filed April 25, 1941 3 Sheets-Sheet 1 INVENTOR. fe/nmelZZZ/e221" BY 7% R. E. HENRY 2,305,005

COATING MACHINE Filed April 25, 1941 3 Sheets-Sheet 2 Dec. 15, 1942.

Dec. 15, 1942. I R. E. HENRY 0 COATING MACHINE Filed April 25, 1941 3Sheets-Sheet 3 Patented Dec. 15, 1942 COATING MACHINE Rommel E. Henry,Longview, Tex, assignor to Pipe Line Service Corporation, Franklin Park.111., a corporation of Illinois Application April 25, 1941, Serial No.390344 13 Claims. (01. 91-32) This invention relates to machines forapplying coating materials to pipe and the like, and

has for its principal object the provision of a machine that will applyto the pipe a coating that is devoid of holidays, pinholes or otherimperfections.

The principal object of the invention is the provision of a coating shoefor'forming a bath of coating material that is free from entrapped .gasand in whichthe pipe is immersed.

the provision of a shoe which is adjustable so,

that the thickness of the film of coating materi applied to the pipe maybe varied.

Still another object of the invention lies in the provision ofarrangements for supplying the shoe with coating materials that are freefrom entrapped gas bubbles and the like.

Further objects of the invention, not specifically mentioned here, willbe apparent from the detailed description and claims which follow,reference being had to the accompanying drawings in which a preferredembodiment of the invention is shown by way of example and in which:Figure 1 is an elevational view of a portion of a machine, partly insection, showing the coating shoe and mounting therefor;

Figure 2 is a cross-sectional view, taken substantially along the line2-2 of Figure 1, and

drawn to an enlarged scale; and

Figure3 is an elevational view, partly in sec tion, showing the coatingshoe construction.

Pipes, pipe lines and the like, are frequently protected from corrosionand electrolysis by an application of a coating material. In certaininstances, a wrapper or wrappers are applied over the coating materialbefore the same has set, with the result that the wrapper is imbedded inthe coating material and thereby bonded to the pipe to afford additionalprotection. In other instances, the coating material alone is reliedupon to protect the pipe.

The coating material is usually applied hot and on cooling forms afairly solid film or sleeve around the pipe and to be effective, it isnecessary that thesleeve so formed be free from holl-' days, pinholes-or other imperfections through which moisture may enter and come intocontact with the pipe. In instances where a wrapper is appliedimmediately on top ofthe coating and before the coating has cooled. thetension under which the wrapper is applied trowels the coating and tendsto squeeze out of it any entrapped gas and also tends .to move thecoating into holidays that may have been left by thecoating shoe. Ininstallations where no wrapper is used, this trowelling action is notpresent, and if the coating is to be free from imperfections, thecoating shoe itself must be capable of applying a holiday free mm on thepipe. v

. It has been found that a goodly portion of the holidays in the coatingmaterial are the result of gas entrapped in the coating materialsupplied to the shoe. This is particularly true when the coatingmaterial contains solvents which vaporize at or near the temperature atwhich the coating material is applied. It has been the practiceheretofore to supply coating material to the shoe from a tank ofmaterial by pumping the same to a point above the pipe and then allowingthis material to flow over the pipe. In-cert'ain instances, the shoesused embrace only the lower half of the pipe and in other instances, afull shoe encircling the pipe is employed and the coating material isdropped into a funnel-like projection on the top of the shoe. It hasbeen found that permitting the coating material to drop into the shoe oron to v the pipe causes a certain amount of air to be entrapped in thematerial and that this entrapped air may cause bubbles to be formed inthe coating on the pipe.

In accordance with the teachings of the present invention, the flow ofcoating material is reversed, that is, the pump forces the materialthrough a suitable supply line that leads into the bottom of the shoe,the material flowing upwardly through the shoe and excess materialescaping from the shoe through an overflow port located on the topthereof. The pump is arranged to draw coating material from the bottomof the tank and is protected so that it cannot pick up coating materialwhich has just fallen back into the tank. with this arrangement, air orgas entrapped in the coatingmaterial by the overs. flow falling backinto the pool of such material is allowed to escape before the materialis recirculated through the system, with the result that the stream ofmaterial flowing from the pump to the coating shoe is free from gas orsecond or so-called travelling type machine wherein the pipe remainsfixed and the machine travels therealong to produce the relativemovement between the shoe and pipe by which the coating is applied tothe pipe. The coating shoe or the instant invention may be used equallywell in machines of either type. Most static a type machines, and sometravelling type mat-- chines, apply a wrapper immediately over thecoating material and when the shoe of the present invention is used insuch a combination, the work turned out by the machine is improved andwhen subjected toelectrical tests for detecting holidays, fewerimperfections are found.

Referring now to the drawings in more detail, particularly Figure 1,- aframe 9 with a tank 2 v is disposed beneath the frame and connectedthereto by suitable supports 3. The frame may well be a part of thetravelling type coating machine shown in Patent No. 2,188,001 issued toDuaei, et a1., January 23, 1940, or the stationary machine of the typeshown in Patent No. 2,048,557 issued to Michelson and Duaei July 21,1936. The details of frame construction form no essential part of thepresent invention and the frame has been shown diagrammatically herein,reference being had to the foregoing patents for such details as needed.

The coating shoe consists of a pair of rings 3 and 5 between which is asheet metal wall i5 forming with the rings a generally cylindrical shoethat embraces the pipe. The rings and walls are preferably weldedtogether, as indicated at i, so as to form a rigid structure capable ofwith standing the rough usage to which it will be subjected.

In order to permit the shoe to betakenoif of and put on the pipe lineand to permit it to ride over welds or other obstructions thereon, the

rings 4 and 5 and the wall d are formed in a these sections containsears 8 and the two upper ones contain co-operating ears 9, these carsbeing pierced to permit pins iii to be projected therethrough to form ahinge connecting the three sections together. Projecting outwardly fromthe two upper sections of the shoe are bosses ii to which supportinglinks by which the shoe is supported on the frame are attached.

In the embodiment shown in the drawings, a shaft i2 is supported upcnthe frame 5 by suitable bearings and carries cell crank levers i3 fixedthereto. Pivoted to these levers are generally L-shaped it which supportat their free ends links I5 that are connected to the ears ii on theshoe. Each link contains a spring it so as to render the same resilientand permit the shoe to move a limited distance vertically oi the frame.The particular construction of linkage shown in the drawings is shown byway of example and may be modified within the teach ings of theinvention.

Shaft I2 also carries a crankarm it and when it is desired to lower theshoe away from the pipe, this arm is rotated in clockwise direction,

I aecaocs Figure 1, moving the shaft and link to lower the pivotalconnection between the bell crank levers and links it. This movementlowers the links it causing the shoe first to open and then to drop awayfrom the pipe into the position in which it is shown in dotted lines inFigure 2. The rotation of crank it in the opposite direction will raisethe shoe and reengage it with the pipe.

As will be seen best in Figure 3, the ring 5 is rounded to form anentrance port ii leading into the shoe, this ring being of such sizethat the innermost edge of the port engages the pipe fairly snugly tocenter the pipe therein. The ring l contains a similar flared edgeleading out of the shoe. This ring is slightly larger than the ring 5 sothat the exit port 18 has a diameter equal to the outside diameter ofthe pipe, plus twice the thickness of the minimum thickness of coatingthat the shoe is designed to apply.

In order to center the shoe upon the pipe, two spacing screws 28 arelocated in the bottom member of the shoe adjacent the ring 5, and aplurality of spacing screws 2| are disposed adjacent the ring t. Asshown, six screws 2i are employed although this number may be varied.Screws 2U engaging the bottom side of the pipe relieve the bottomportion of ring 5 of wear which would be occasioned by the tension ofthe springs 96, pulling the shoe upwardly and the lower ones of thescrews 2i perform a similar function. By

v proper adjustment of the screws, the shoe is centered on the pipe sothat the coating applied thereto is of uniform thickness around thepipe.

The bottom section 36, Figure 2, of the wall 5 contains a nipple 3ilocated near the forward end of,the shoe, that is, near the end ring 5.The nipple is attached in any preferred manner such as by welding andcommunicates with the inside of the cylindrical shoe.

Located within the tank 2 is a pump 32 having connected to its outletside a flexible hose 33 that is connected to the nipple ii. The painwhich may be of any preferred type, forces material from the tank 2through the pipe 33 into the shoe, where this material encircles thepipe and is confined in the shoe by the end rings d and 5. Rising out ofthe top of the shoe at the junction of the two sections thereof' is agenerally rectangular box-like member 3'3 forming a reservoir into whichthe coating material travels. It will be noted in Figure 1 that the endwalls of the reservoir 36 are higher than the central section of thesidewalls, this arrangement forming a weir 35 through which the excessmaterial in the reservoir overflows, falling down over the outer surfaceof the shoe and into the tank 2.

The coating material returning to the tank may entrap gas or air and toprevent material containing gas or air from being drawn into the pump,the tank 2 is provided with a bafiie as extending from the top edge ofthe tank and above the upper surface of the coating material thereindown to a line near the bottom of the tank. Bubbles formed in thematerial by the overflow of the shoe are confined in the section of thetank. away from the pump and it is there by assured that the pump willsupply to the shoe only gas free material.

It will be understood that the tank 2 may be provided with suitablearrangements for applying heat to the material contained therein. butsince these arrangements form no part of the instant invention, theyhave been omitted from 4and the p portion otthe pipe. 1

:2 and a may be fixed to n M M ierred mannerysuch as by weldingi andf.may

7 to the left. To preve links, such as chains];

venting the coatingsh asoaoos aroundthe the avoid an unnecessarycomplicationthereoi. G d a .1 52 d Coating materials that the:shoejoithe present invention must handle vary; considerably at ap- I plicationtemperatures. Certain of these. materials, known generally as enamels,are of the g consistencyof cream. atproper application temperature,whileothers, such as No-Oxid'? ror example, are much thinner havingconsistency morenearly' that 01' water,

, It willbeob served' that coating material To control the flow'oimaterial under these 1 1 conditions, a baille or bailies 22 maybeattached to the bottom section "of the wall [of the shoe. Thisbamemeans extends into juxtapositionlto'thepipe andexte'nds'slightlybeyond the Junctions oi the bottomsection '30 with the up- 'per sectionsof the shoe. Each upper section A carries'a similarfibame means 23 whi hoverlaps the bai'iie 22, as shown in Figure :extend t Ew thm'amt m iseam an inch 01' the 7 With bodie 22 and-1234 "quid ing the shoe throughnip wardly around? the ..fpipe .g1thou gh "a' "liinited amount -01 itsows" slon theipipe horizontally through the space betweenjthe' baiiieand the pipe. The pressure occasioned by the velocity oi thejliquid''enteringthe pipe is thus blocked of! from the ring 4 alongthebottom'portion oi the pipe and the liquid against 'this ring is, in

r a nine in the space between ur mia: wall loiths shoe and the pipe, thepump being rui'i'iasten'ough to supply. suflicient material to ,keep theshoe iull, and overflowing at all times.

As the shoe moves along the pipe, or the pipe. moves through the shoe,the coatingmaterial in which the pipe is submerged adheres to the pipeand a certain amount of this material flowsfout oi the shoe in the spacebetween the ring 4 I and the pipe. .The adjusting screws 2| areset Jsothat the amount of material so escaping from o i The movement-ct thecoating material upwardly in the shoe scrubs the pipe iree of air 'eii-I the shoe will be correct forthe desired thickness of coating.

trapped in pits or irregularities in the surface. Thisv is P rticularlynoticeable on reconditioned pipewhpse surface is apt to contain pits inwhich air has been entrapped'with shoes or the .prior Air brought intothe shoe oithepresent inventionis scrubbed onto! the pits into thecoatingmaterial and allowed to escape from the: shoe in the overflow.Since the air is lighter than the coating material, it naturally tendsto risetherehand the upward movement of the material aim rather thanhinders'this natural movement. v Should a or other obstructionappearjhg. the pipe, it engage the rounded face or the 3 entry port I1and force the shoe'opensufliciently to permitit to; embrace the weld.,As will be seen inFigure 2, the adjacent ends of the three sec- [flowsmainly upi tions'of the shoe are provided with overlapping plates 40 and4|,whichclose the-gaps between the sections as theshoe opens to permitpassing a weld,'therebv .preventingyan. excessive loss of a materialfr'omtheshoe; Plates 40 located at, the

ends 'oi' thefreservoir 34 extend-from the top J thereoifidowninto closeproximity to the pipeandj f are. attachedlto'on'e section of. thereservoir wall and overlap the abutting section. If desired, the

- tree endorthese'platesM may be bevelled, as

at 42 so thatthey will cut through the material-in the reservoir as-theshoecloses.

the main, only under the pressure of the. hydrostatic head, and theamount offliquid passing f the device, after" the coatbrought toapplication pis started with the coatcoating shoe intoathe'flcoatingmaterial so as'to more quickly bring it up to proper temperature. IAlter the hot coating material has flowed through the shoe suflicientlyto prepare it for. operation,

crank l8 isoperated toengage the. shoe with the pipe. a e .vA relativemovement between the shoe and pipe is'then setup either by moving themachine along the pipefor by moving the pipe 7 through the machine As'viewed in Figurel,

this movement is as e pipe 3'! were" moving the coating shoe from beingdragged along'wi {the pipe, suitable drag .m moving to the left. Gasfree coating material 'iorcedthrough the d 1 rom thepipe. In certaininstances it mayfbefadvantageous to lower the are attached to the shoe O"the arrangement pre- 45 out of the shoethroushjthe ring] is "limited. f-,While only one ba'ifle 22 and 23 is shown, a pmrality of similarbaiiies may be used, forming; in f efiect, a labyrinth packingalong thepipe. This may be advisable-in extreme cases although ordi-.

.narily one set ot baiiies will be sumcient. Y

-material. Preferably the shoe sections are formed so that Plates 4|are-flxed'upon rings 4 and I onone side "of th butting ends .oi thesections thereof and overlaptheothersections. These platesextendi'rom'theouter wall 8 ofthe shoe into close proximity, oi the pipe. Eachplate :4l is fixed to one 5 section and overlaps the adjacentise'ctionand the free ends of the plates; are. bevelled as areplates 40 to cutthrough the :material as the shoeis 'being closed. By this arrangement,it is assured that the coating material in the shoe will completelysurround the pipe at all times and a weldv passing through theshoe willbecoated with'the the adjacent ends, abut tightly together when the shoeis set toapply. a minimum thickness coating on the pipe. 'Whenthe shoeis adjus ed .i'or applying. a thicker coating, the ends will be spacedapart slightly and the plates 40 and 41 serve to preventexcessive-lossor coating materiali'romtheshoe.

Whenever it isnecessaryto stop the relative movement or the pipe andshoe, as will be the 7 permit replenishing'thesupply oi wrappingmaterial to the machine, aswell as case frequently to for othercauseathe shoe may be dropped away flexible pipe as into thehdtto or theshoe hows rrom the pipe and, if desired, the pump mayigbe.stoppedswithout impeding the work:

things are in readiness to resume operatio the pum is-started and usuflicient hot material has been pumped throughrthe pipe 31 to be surethat the same free 01'. the shoe maybe w res elevated into engagementwith the pipe and work The shoe of the present invention is possessed ofmany advantages} Through its operation of feeding coating materiaffrom.the bottom of a tank' upwardly through the shoe under pressure lgenerated by'the pump, holiday free coatings may be applied to thepipeeven though the material used contains solvents which are vaporized inwhole or in partat the temperatures employed in the-process. Air trappedin pits in the pipe is scrubbed outof the pits and carried out of theshoe with the excess material. Excess material returning to the. tankwill entrap a certain amount of air which, being lighter than thematerial, escapes therefrom long before the materail again enters thecirculatory system; The shoe may be readily lowered from the pipe whenit is necessary to clear an obstruction orwhen it is necessary to shutdown'the machine and the. danger of 'freezingthe shoe on the pipe by thesolidification of inated.

While I have chosen to show my invention by illustrating and describinga preferred embodiment. of it, I have done so by-way of example only, asthere are many modifications and adaptations which can be made by oneskilled in the art within the teachings of the invention;

Having thus complied with the statutes; and shown and described apreferred embodiment of coating material therein is elimmyinvention,what I consider new and desire to have protected by Letters Patentis'pointedcut in'the appended claims; What is claimed'is:

1; In a machine for applyin coating material to a. pipe during arelative movementjofthe machine and'pipe, a generally cylindrical shoeen- .oirciing the pipe, a'supply line leading into the llnttom'of saidshoe, means for forcing coating material through said lirie and shoe andaround said-pipe, and overflowmeans at the top of said shoe forpermitting excess material to flow out of said shoe and over the outsidethereof.

' -2, In a machine for applying coating material to a pipe during arelative movement of the machine and pipe, a tank disposed beneath thepipe 'that'is to be coated and-containing'a supply 'of coatingmateriaL'ia shoe, means for-supporting said shoe above said tank inengagement-with the pipe, means for supplyin gas free coating materialto said shoe, comprising, a' pump submerged in thec'oating material anda feed pipe leading out of. the pump and into the bottom'of said shoethrough which the pump forces material upwardly through the shoe and outofthe .upwardly through the shoe and out of the top thereof, and bafiiemeans guarding said pump from coating material dropping from said pumpinto said supply of coatingmaterial.

4. In amachlne for applying coating material to pipes and the likeduring a relative movement the pipe that is being coated, a shoeencircling said pipe, a tank disposed beneaththe pipe, a shaft on saidframe, apair of bell crank levers on said shaft, link means connectingsaid levers to said shoe to support the shoe on the frame, meansconnected between the shoe and frame for steadying the shoe with respectto the frame during the relative movement of the machine and pipe, apump in said tank, and flexible pipe means connecting the pump to thebottom of the shoe to permit the pump to force coating material from thetank upwardly through the shoe and around the pipe that is being coated.

5. In a machine for applying coating material to pipes and the likeduring a relative movement of the machine and pipe. frame disposed abovethe pipe that'is being coated, a tank below the pipe, a coating shoesuspended from said frame and encircling the pipe, a baflie in said tankextending from the top' of the same into juxtaposition to the bottom anddividing the tank into two compartments, a pump in one of saidcompartments, and a flexible tubing extending from said pump to thebottom of said shoe-to conduct coating material from the tank to andthrough the shoe,"said shoe being suspended over the second one of saidtank compartmentsso that material dropping from the shoe into the tankfalls into said second compartment.

. 6. vIn a machine for applying coating material to a pipe during arelative movement of the machine and .pipe, a generally cylindrical shoeencircling the pipe, a supply line leading into the bottom of said shoe,means for forcing coating mitting excess material'to' flow out of saidshoe,

and over the outside thereof.

7 In a machine for applying coating material to pipes and the like,-aframe, acoevting shoe comprising aplurality of sections hinged togetherto form a generally cylindrical member through which the pipe that is.being coated extends coaxially, a resilient link attached to each oftwo of said shoe sections extending toward said frame, means on theframe engaging saidlinks to support the shoe with respect 1 thereto,saidmeans including over-center levers operable to lower the shoe topermit" the same to open and fall away from the p pe, at flexible pipeleading into the bottom of the shoe, means including a pump for forcinga coating material through said pipe and shoe and around the pipe, andoverflow :means on the top of the shoe for directing excess coatingmaterial flowing outtof the shoe therethrough over the outside of theshoe.

8. 'In a coating machine, a shoe encirclingthe Q pipe that, is to becoated, and adapted to move with respect thereto, an end wall projectingradially inwardly from one end of said shoe and slidably engaging thepipe, an end wall projecting radially inwardly from the other end ofsaid shoe and terminating on a circle spaced from the outer surface ofthe pipea distance equal to the thickness of the coating to be appliedthereto, a plurality of spacing means projecting through said "shoebetweensaid end wallsand engaging 'said pipe to space said latter endwall uniformly therefrom, a tank containing coating material that is tobe applied to the pipe, means includof the machine. and pipe, a framedisposed above 76 8 a pump for feeding said material into the botto flowfrom said shoe over the outside thereof i and to return to said tank.

9. In a machine for applying coating material to a pipe during arelative movement 01' the machine and pipe; a generally cylindrical shoeencircling the pipe, a supply line leading into the bottom of said shoe,means for forcing coating material through said line into said shoe,means for directing said material upwardly through said shoe and aroundthe pipe, and overflow means at the top of said shoe for permittingexcess material to flow out of and over the outside of said shoe.

10. A shoe for coating pipe comprising, a plurality of segmentalmembers, means yieldingly holding said members together to form a.generally cylindrical member which surrounds the pipe,

means for spacing the shoe concentrically on the pipe, means for feedingcoating material into the shoe at a point beneath the pipe, means fordirecting said material upwardly through the shoe and around the pipe,and overflow means for permitting excess material to escape from theshoe at the top thereof.

11. A shoe for coating pipe comprising a plurality of segmental members,hinge means yieldingly holding said members together to form a generallycylindrical member which surrounds members at uniform distance from thepipe, a

nipple through which coating material is fed into the shoe at a pointbeneath the bottom or the pipe, baflle means in the shoe for causingsaid material to flow upwardly through the shoe and around the pipe, andoverflow means for permitting excess material to escape from the shoe at1 the top thereof.

12. A shoe for coating pipe, comprising, three sections which areregistered together to form a generally cylindrical body which encirclesthe pipe, hinge mean connecting said sections togather, a flexible tubeconnected to and leading through the bottom one of said sections intothe shoe, means on the ends of said shoe extending into juxtaposition tothe pipe for confining coating material in theshoe,;overflow meansleading out "or the top of the and spacing means engaging the pipe andshoe for centering the shoe coaxially of the pipe.

13. A coating shoe comprising, three sections which together form agenerally cylindrical body, hinge means swingly connecting two 01 saidsections to the third, a nip' e depending from said third section to--receive a pipe through which coating material is supplied to the shoe,end walls projecting radially inwardly to form flanges which assist inconfining coating material in the shoe, wall means projecting outwardlyfrom each of said first and second sections, said wall means forming areservoir, extending upwardly from the shoe through which excess coatingmaterial may flow and spill over the outside face of the shoe, meansprojecting outwardly from said flrst and second sections toreceivemeansfor supporting and steadying the shoe, and spacing means extendinginwardly from said sections for centering the shoecoaxially with a pipe.

REMMEL E. HENRY.

